Klyuchevskite is an extremely rare sulfate mineral formed as a product of fumarolic activity at the Tolbachik volcano in Russia. It typically appears as bright green, thin tabular crystals or delicate encrustations inside volcanic vents. Collectors prize it for its unique chemical composition and highly specific type locality.
Is this klyuchevskite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch klyuchevskite with a known reference. Klyuchevskite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Klyuchevskite leaves a pale green streak.
- 3Read the lusterHold the specimen under a strong light. Klyuchevskite typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: green, yellow-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, crusts, aggregates.
Often confused with
Klyuchevskite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads submetallic on Klyuchevskite and vitreous on Alumoklyuchevskite.
How to tell apart: Lammerite is the harder of the two (Mohs 3.5 vs. 2-2.5); streak differs, so Klyuchevskite leaves pale green, Lammerite leaves light green; luster reads submetallic on Klyuchevskite and vitreous on Lammerite.
Often found alongside klyuchevskite
Minerals reported to co-occur with klyuchevskite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₃Cu₃Fe³⁺O₂(SO₄)₄
- Mohs hardness
- 2-2.5
- Density
- 3.32 g/cm³
- Colors
- Streak
- Pale Green
- Luster
- Submetallic
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Crusts, Aggregates
- Cleavage
- On {h0l}, Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Fumarolic Deposits of Volcanic Vents
Where rockhounds find klyuchevskite
Classic worldwide localities
- Tolbachik volcano, Kamchatka Peninsula, Russia
Field-hunting tip
Look in fumarolic deposits of volcanic vents country, the host setting where klyuchevskite typically forms. If you start seeing alumoklyuchevskite, lammerite, tenorite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify klyuchevskite?+
Where is klyuchevskite found?+
Is klyuchevskite safe to handle?+
What rocks look like klyuchevskite?+
What minerals are found with klyuchevskite?+
What kind of rock does klyuchevskite form in?+
What is klyuchevskite used for?+
Find klyuchevskite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
